The invention concerns a cooling water pump for combustion engines having a bearing cover which can be affixed to a housing in which a shaft having an impeller is rotatably supported by means of a bearing. A sealing element disposed in the interstice between impeller and bearing seals the cover with respect to the shaft. In the remaining interstice between bearing and sealing element, provision is made for an annular chamber having a ventilating device.
A cooling water pump of this type is known from German patent DE 38 21 352. The annular chamber with the ventilating device is provided to remove leakage liquid and keep this liquid away from the bearing.